Abstract
Background: To date, multiple organ failure complicating HIT has been reviewed in a limited patient (pt.) numbers in the medical literature.
Objectives: (1) To describe the clinical features of pts. with HIT who developed the failure of ≥ 2 organs termed multiple organ failure syndrome (MOFS); (2) to determine the prevalence/incidence of MOFS HIT in a cohort of CAMC HIT Registry/open heart surgery (OHS) pts.
Design: Retrospective case series identified from an IRB-approved HIT Registry. Setting: Tertiary-care medical center.
Patients: 19 patients ≥ 18 yrs who presented from 1.1.00 to 12.31.04 with HIT ± thrombo-embolic complications (TEC) confirmed by serological (HPF4 ELISA, GTI) or functional (HIPA) HIT assays during (n=18) or after (n=1) a recent hospitalization with UFH exposure. Mean age: 71 yrs. (range, 49–84); women: 47%. UFH exposure settings (n): CABG alone (6) or with valve replacement (4), valve replacement alone or RV repair (1 each), aortic dissection repair (1), embolectomy or SBO (2 each), Whipple procedure (1; non-CA), atrial fibrillation (1). Measurements: Classification of MOFS: failure of ≥ 2 organs [e.g., brain, GI tract, liver, kidney, heart, lung (due to PE)] as modifications of the methods of Lefering R. et al (2002) and the Society of Thoracic Surgeons National Adult Cardiac Surgery Database, Version 2.52.1; platelet counts, clinical outcomes.
Results: The prevalence of MOFS in HIT Registry pts. was 4.7% (19/404). During this time, the incidence of MOFS complicating OHS HIT pts. in the total OHS pts. was 0.12% (13/11,018). HIT was first suspected a mean of 10d (range, 1–38) from initial UFH exposure and a mean of 4.7d (range, <1d-25) after UFH was D/C’d where overall platelet counts [mean, 74x109/L, (range, 22- to 125-)] showed a 66% decrease from baseline [mean, 218 x 109/L, range (95- to 498-)]. At this time, 12 (63%) pts. had thrombocytopenia alone, 7 (37%) pts. had both thrombocytopenia and TEC, and 13 (68%) pts. had a total 19 organ failures (OF).: 1 OF: 8 pts.; 2 OF’s: 4 pts.; and 3 OF’s: 1 pt. At the time HIT was first suspected, the kidney (47%) and brain (32%) were the most frequent sites of organ failure. After the time HIT was first suspected and diagnosed, 17 (89%) pts. had developed ≥ 1 additional new OF: 1 OF: 7 pts.; 2 OF’s: 5 pts.; 3 OF’s: 5 pts. The liver (39%), kidney (23%) and GI tract (19%) were the most frequent sites of new OF’s. The mean/median overall number of organ failures/pt. were 2.6/2.0 (range, 2 to 4). Direct thrombin inhibitor (DTI) therapy was initiated in 17 (90%) at a mean of 2.5d (SD: 4.0) (range, 0–13) from the date HIT was first suspected: lepirudin (9) or Argatroban (8); (2 were not treated due to family wishes or late recognition). Lepirudin was switched to Argatroban in 2 pts. due to worsening renal failure and Argatroban was switched to lepirudin in 2 pts. due to worsening liver failure. The mean length of DTI therapy was 8.8 d (range, 1–20). Compared with non-MOFS HIT Registry pts. (n=395), MOFS HIT pts. had more fatal outcomes [95% (18/19) vs. 11% (45/395); p = 3.2x 10−15], major bleeding events [26% (5/19) vs. 6.3% (25/395); p = 0.008], and amputations [11% (2/19) vs. 1.5% (6/395); p = 0.047].
Conclusions: Although uncommon, MOFS may be the initial manifestation of HIT and is associated with catastrophic outcomes. Compared to non-MOFS HIT pts., MOFS HIT pts. had an increased rate of fatal outcomes, major bleeding events, and rates of amputation. In a subset of HIT pts., MOFS hampered the delivery of utilized DTI’s. Our data also suggest the need for earlier HIT recognition and DTI interventions.
Platelet counts during pregnancy in Chinese women
